Fast-swirl space non-cooperative target spin state measurements based on a monocular camera.

Measuring the motion state of space non-cooperative targets is in the fields of space on-orbit services and debris removal. This paper proposes a method for the measurements of the spin rate of fast-swirl non-cooperative targets through a monocular camera, for image features that have been degraded at a medium and long distance. First, the coordinate system between the tracking satellite and the target is established, and the relationship between the target spin period and its image projection angle is deduced. An image processing method which can extract the projection angle of the target image stably under complex illumination conditions is then proposed. Next, considering the characteristics of the sequence projection angle of the fast-spinning target at a long distance, the spin rate of the target is calculated using a sinusoidal polynomial fitting method. The proposed method is validated by simulated and on-orbit data. Experiment results show that the method has strong adaptability, measurement reliability and practical engineering application prospects. • Measuring the spin rate of non-cooperative targets through monocular camera images. • Proving the mathematical principle of the spin rate measurement. • Applied to long-distance, image feature degradation and fast spin small targets. • Fora 60°/s fast-spinning target, the measuring standard deviation is 0.05°/s. • Giving ground simulation and space images data verification test results. [ABSTRACT FROM AUTHOR]